[deliverable/linux.git] / net / ipv6 / xfrm6_mode_ro.c

/*
 * xfrm6_mode_ro.c - Route optimization mode for IPv6.
 *
 * Copyright (C)2003-2006 Helsinki University of Technology
 * Copyright (C)2003-2006 USAGI/WIDE Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
/*
 * Authors:
 *	Noriaki TAKAMIYA @USAGI
 *	Masahide NAKAMURA @USAGI
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/stringify.h>
#include <linux/time.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

/* Add route optimization header space.
 *
 * The IP header and mutable extension headers will be moved forward to make
 * space for the route optimization header.
 */
static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ipv6hdr *iph;
	u8 *prevhdr;
	int hdr_len;

	iph = ipv6_hdr(skb);

	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
	skb_set_network_header(skb, -x->props.header_len);
	skb->transport_header = skb->network_header + hdr_len;
	__skb_pull(skb, hdr_len);
	memmove(ipv6_hdr(skb), iph, hdr_len);

	x->lastused = get_seconds();

	return 0;
}

static struct xfrm_mode xfrm6_ro_mode = {
	.output = xfrm6_ro_output,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_ROUTEOPTIMIZATION,
};

static int __init xfrm6_ro_init(void)
{
	return xfrm_register_mode(&xfrm6_ro_mode, AF_INET6);
}

static void __exit xfrm6_ro_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm6_ro_mode, AF_INET6);
	BUG_ON(err);
}

module_init(xfrm6_ro_init);
module_exit(xfrm6_ro_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_ROUTEOPTIMIZATION);
Commit	Line	Data
	1	/*
	2	* xfrm6_mode_ro.c - Route optimization mode for IPv6.
	3	*
	4	* Copyright (C)2003-2006 Helsinki University of Technology
	5	* Copyright (C)2003-2006 USAGI/WIDE Project
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	19	*/
	20	/*
	21	* Authors:
	22	* Noriaki TAKAMIYA @USAGI
	23	* Masahide NAKAMURA @USAGI
	24	*/
	25
	26	#include <linux/init.h>
	27	#include <linux/kernel.h>
	28	#include <linux/module.h>
	29	#include <linux/skbuff.h>
	30	#include <linux/spinlock.h>
	31	#include <linux/stringify.h>
	32	#include <linux/time.h>
	33	#include <net/ipv6.h>
	34	#include <net/xfrm.h>
	35
	36	/* Add route optimization header space.
	37	*
	38	* The IP header and mutable extension headers will be moved forward to make
	39	* space for the route optimization header.
	40	*/
	41	static int xfrm6_ro_output(struct xfrm_state x, struct sk_buff skb)
	42	{
	43	struct ipv6hdr *iph;
	44	u8 *prevhdr;
	45	int hdr_len;
	46
	47	iph = ipv6_hdr(skb);
	48
	49	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
	50	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
	51	skb_set_network_header(skb, -x->props.header_len);
	52	skb->transport_header = skb->network_header + hdr_len;
	53	__skb_pull(skb, hdr_len);
	54	memmove(ipv6_hdr(skb), iph, hdr_len);
	55
	56	x->lastused = get_seconds();
	57
	58	return 0;
	59	}
	60
	61	static struct xfrm_mode xfrm6_ro_mode = {
	62	.output = xfrm6_ro_output,
	63	.owner = THIS_MODULE,
	64	.encap = XFRM_MODE_ROUTEOPTIMIZATION,
	65	};
	66
	67	static int __init xfrm6_ro_init(void)
	68	{
	69	return xfrm_register_mode(&xfrm6_ro_mode, AF_INET6);
	70	}
	71
	72	static void __exit xfrm6_ro_exit(void)
	73	{
	74	int err;
	75
	76	err = xfrm_unregister_mode(&xfrm6_ro_mode, AF_INET6);
	77	BUG_ON(err);
	78	}
	79
	80	module_init(xfrm6_ro_init);
	81	module_exit(xfrm6_ro_exit);
	82	MODULE_LICENSE("GPL");
	83	MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_ROUTEOPTIMIZATION);